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			67 lines
		
	
	
	
		
			1.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			67 lines
		
	
	
	
		
			1.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|     This file is part of TON Blockchain Library.
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| 
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|     TON Blockchain Library is free software: you can redistribute it and/or modify
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|     it under the terms of the GNU Lesser General Public License as published by
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|     the Free Software Foundation, either version 2 of the License, or
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|     (at your option) any later version.
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| 
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|     TON Blockchain Library is distributed in the hope that it will be useful,
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|     but WITHOUT ANY WARRANTY; without even the implied warranty of
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|     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|     GNU Lesser General Public License for more details.
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| 
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|     You should have received a copy of the GNU Lesser General Public License
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|     along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
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| 
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|     Copyright 2017-2020 Telegram Systems LLP
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| */
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| 
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| #pragma once
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| 
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| #include <atomic>
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| #include "td/utils/MovableValue.h"
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| #include <memory>
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| 
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| namespace td {
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| template <class T>
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| class SharedState {
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|  public:
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|   friend class Guard;
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|   class Guard {
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|    public:
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|     Guard(Guard &&) = default;
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|     Guard(SharedState<T> *self) : self(self) {
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|       CHECK(!self->data_->is_locked.exchange(true));
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|     }
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|     ~Guard() {
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|       if (self.get()) {
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|         CHECK(self.get()->data_->is_locked.exchange(false));
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|       }
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|     }
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|     T *get() {
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|       return &self.get()->data_->data;
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|     }
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|     T *operator->() {
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|       return get();
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|     }
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| 
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|    private:
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|     td::MovableValue<SharedState<T> *> self;
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|   };
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| 
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|   auto lock() {
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|     return Guard{this};
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|   }
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|   auto unsafe() {
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|     return &data_->data;
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|   }
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| 
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|  private:
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|   struct Data {
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|     std::atomic<bool> is_locked{};
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|     T data;
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|   };
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|   std::shared_ptr<Data> data_{std::make_shared<Data>()};
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| };
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| }  // namespace td
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